Device for preparing a beverage with a foam layer

ABSTRACT

A device that includes a beverage unit for delivering a beverage under pressure, at least one nozzle in fluid communication with the beverage unit to generate a jet of beverage, a receiving unit with a chamber with at least one drain opening for delivering the beverage and a jet impact member within the chamber and having a top that lies free from an inner wall of the chamber. The nozzle and the jet impact member are oriented such that the jet hits against a portion of the top of the jet impact member to form a mist of the beverage that subsequently leaves the drain opening as a beverage with a foam layer. The device is constructed such that air can only be supplied to the chamber through the at least one drain opening and/or through an air supply channel which extends through the jet impact member into the chamber.

This is a divisional application of U.S. patent application Ser. No.10/581,352, filed Jun. 1, 2006.

The invention relates to a device for preparing a beverage suitable forhuman consumption with a fine-bubble foam layer, such as coffee or milkwith a fine-bubble foam layer, provided with a beverage unit forsupplying the beverage under pressure, at least one nozzle which is influid communication with the beverage unit for supplying the beverage tothe nozzle such that the latter can generate a jet of the beverage, anda receiving unit into which the jet is directed for obtaining saidbeverage with the fine-bubble foam layer.

The invention also relates to a method of preparing a beverage suitablefor human consumption with a fine-bubble foam layer, such as coffee ormilk, in which method a liquid jet comprising the beverage is generatedand said liquid jet is supplied to a receiving unit such that the jetenters the receiving unit under pressure for obtaining the beverage withthe fine-bubble foam layer.

The invention further relates to a unit provided with such a receivingunit and a holder for accommodating a product to be extracted and/or tobe dissolved, such as coffee, tea, and/or a dairy creamer.

The invention further relates to a unit provided with a part of such areceiving unit and a holder for accommodating a product to be extractedand/or to be dissolved such as coffee, tea, and/or a dairy creamer.

The invention further relates to an assembly of such a unit and a padwhich is accommodated in the holder of the unit.

Such a device and such a method are known from a possible embodiment ofa device from European patent application EP 0 878 158.

In the known device, the receiving means are provided with a bufferreservoir which comprises a bottom with vertical side walls in thisexample. The jet is squirted into the buffer reservoir, which is thusfilled with the beverage to be processed, during use. This creates aliquid surface in the buffer reservoir. The liquid jet is then squirtedinto the liquid surface, whereby air is beaten into the beverage so thata fine-bubble foam layer is generated. The buffer reservoir is furtherprovided with an outlet arrangement for draining the beverage with thefine-bubble foam layer from the buffer reservoir.

Squirting of the beverage into the buffer reservoir stops after sometime. The buffer reservoir will subsequently empty itself in thisexample. The buffer reservoir may for this purpose be provided with aspecially adapted drain opening in the bottom of the buffer reservoir.

Although a beverage with a desired quality and a fine-bubble foam layeris formed in the known system, it is a disadvantage that it takes sometime before the buffer reservoir has fully emptied. It is especially theaccompanying final dripping that may occupy a comparatively long periodof time. For example, if one cup of coffee is prepared in the knowndevice by the known method, the emptying of the buffer reservoir and thefinal dripping may take half a minute. Final dripping itself may take 20seconds. In addition, the known system has bulky dimensions.

The invention has for its object to provide a device and a method bywhich the problem identified above can be counteracted, if so desired.

The device according to the invention is for this purpose characterizedin that the receiving unit is provided with a chamber having at leastone drain opening for delivering the beverage with the fine-bubble foamlayer and a jet impact member accommodated in the chamber and having atop which lies free from an inner wall of the chamber, the nozzle andthe jet impact member being mutually oriented such that the jet hitsagainst at least a portion of the top of the jet impact member so thatthe beverage, after hitting against the jet impact member, leaves thechamber through the at least one drain opening in the form of thebeverage with the fine-bubble foam layer, while the device isconstructed such that air can be supplied to the chamber exclusivelythrough said at least one drain opening and/or through an air inletchannel which extends through the jet impact member into the chamber.

Since no fluid level needs to be built up in the chamber of the deviceaccording to the invention, said chamber can be emptied comparativelyquickly, if so desired, after the jet has stopped squirting into thechamber, in which case final dripping will be comparatively short. It ismerely necessary that the at least one drain opening of the chambershould be sufficiently large for obtaining a comparatively short finaldripping time. This drain opening can be made sufficiently large, if sodesired, in order to shorten the final dripping period. It is alsopossible to construct such a device with comparatively small dimensions.

If air is supplied to the chamber exclusively through the at least onedrain opening and/or through an air supply channel extending through thejet impact member, it is found that a beverage with a rich, fine-bubblefoam layer is obtained. The chamber can be inexpensively manufactured,if so desired, in that the chamber itself is not provided with an airsupply opening other than the drain opening and/or said air supplychannel.

It holds in particular that the chamber is provided with a product feedopening through which the jet generated by the nozzle is fed to thechamber during use.

It preferably holds here that the product feed opening is formed by thenozzle.

Such a construction is simple without having adverse effects on thesatisfactory operation of the device.

Furthermore, it preferably holds that a space within the chamber betweenthe nozzle and the jet impact member is free from restrictions thathamper a flow of the beverage between the nozzle and the jet impactmember.

Furthermore, it is true in particular that the top is at leastsubstantially directed towards the nozzle. The impact of the jet againstthe top can be comparatively strong as a result of this, so that thebeverage is atomized into very fine particles after the impact. It ispreferably true here that the top of the jet impact member is presentbetween the product feed opening and the drain opening. Preferably,furthermore, the top is at least substantially directed towards theproduct feed opening.

It is true in particular that a surface of the top is concave, convex,or planar. It is found for a convex surface of the top that a mist isobtained with droplets which are substantially homogeneous as regardstheir diameter. This is found to promote the creation of a homogeneous,fine-bubble foam layer.

It is preferably true that a line perpendicular to the surface of thetop in a location where the jet hits the top is at least substantiallyparallel to said jet. As a result, the jet will at least substantiallybe incident perpendicularly to the surface, in which case theinteraction between the jet and the surface is at its greatest. In otherwords, the velocity component of the jet in the direction of theperpendicular is equal to the velocity of the jet itself, i.e. amaximum.

The method according to the invention is characterized in that thereceiving unit is provided with a chamber with at least one drainopening for delivering the beverage with the fine-bubble foam layer anda jet impact member accommodated in the chamber and having a top whichlies free from an inner wall of the chamber, wherein the jet is directedsuch that the jet hits against a portion of the top of the jet impactmember, wherein the beverage after hitting the jet impact member leavesthe chamber through the at least one drain opening as the beveragehaving the fine-bubble foam layer, and wherein air is supplied to thechamber exclusively through the at least one drain opening and/orthrough an air supply channel which extends through the jet impactmember into the chamber.

A possible unit according to the invention is provided with a receivingunit and a nozzle of the device as claimed in any one of the claims 1 to28, as well as a holder for accommodating a product to be extractedand/or to be dissolved, such as coffee, tea, and/or a dairy creamer,wherein the holder, the chamber, the jet impact member, and the nozzleare mechanically connected to one another, while the holder comprises atleast an outlet which is in fluid communication with an inlet of thenozzle.

Another possible unit according to the invention is provided with achamber and a nozzle of the device as claimed in any one of the claims 1to 28, as well as a holder for accommodating a product to be extractedand/or to be dissolved, such as coffee, tea, and/or a dairy creamer,wherein the holder, the chamber, and the nozzle are mechanicallyconnected to one another, while the holder comprises at least one outletwhich is fluid communication with an inlet of the nozzle.

The assembly according to the invention comprises a unit as claimed inany one of the claims 59 to 64 and at least one pad which comprises anenvelope of filter paper and which is filled with the product to beextracted and/or to be dissolved, which pad is accommodated in theholder such that it extends over a bottom of the holder up to a raisedside wall of the holder.

The invention will now be explained in more detail with reference to thedrawings, in which:

FIG. 1 is a cross-sectional view of an embodiment of a device notaccording to the invention for the preparation of a beverage suitablefor human consumption and having a fine-bubble foam layer;

FIG. 2 is a cross-sectional view of a first embodiment of a deviceaccording to the invention for the preparation of a beverage suitablefor human consumption and having a fine-bubble foam layer;

FIG. 3 is a cross-sectional view of a second embodiment of a deviceaccording to the invention for the preparation of a beverage suitablefor human consumption and having a fine-bubble foam layer;

FIG. 4 a is a cross-sectional view of a third embodiment of a deviceaccording to the invention, a unit according to the invention which isprovided with a holder, a nozzle, and a receiving unit, and an assemblyaccording to the invention which is provided with the unit, at least onepad being accommodated in the holder of the unit;

FIG. 4 b is a bottom view of the device of FIG. 4 a;

FIG. 5 a is a cross-sectional view of a fourth embodiment of a deviceaccording to the invention, a unit according to the invention which isprovided with a holder, a nozzle, and a receiving unit, as well as anassembly according to the invention which is provided with the unit, atleast one pad being accommodated in the holder of the unit;

FIG. 5 b is a cross-sectional view of the device of FIG. 5 a;

FIG. 6 a is a cross-sectional view of a fifth embodiment of a deviceaccording to the invention, a unit according to the invention which isprovided with a holder, a nozzle, and a receiving unit, as well as anassembly according to the invention which is provided with the unit, atleast one pad being accommodated in the holder of the unit;

FIG. 6 b is a cross-sectional view of the device of FIG. 6 a;

FIG. 7 a is a cross-sectional view of a sixth embodiment of a deviceaccording to the invention, a unit according to the invention which isprovided with a holder, a nozzle, and a chamber of a receiving unit, andan assembly according to the invention which is provided with the unit,at least one pad being accommodated in the holder of the unit;

FIG. 7 b is a cross-sectional view of the device of FIG. 7 a;

FIG. 8 a is a cross-sectional view of a seventh embodiment of a deviceaccording to the invention, a unit according to the invention which isprovided with a holder, a nozzle, and a chamber of a receiving unit, andan assembly according to the invention which is provided with the unit,at least one pad being accommodated in the holder of the unit;

FIG. 8 b is a cross sectional view of the device of FIG. 8 a;

FIG. 9 shows a first alternative embodiment of a jet impact member thatmay be used in the devices of FIGS. 2 to 8 and 11;

FIG. 10 shows a second alternative embodiment of a jet impact memberthat may be used in the devices of FIGS. 2 to 8 and 11;

FIG. 11 shows an eighth embodiment of a device according to theinvention for the preparation of a beverage suitable for humanconsumption and having a fine-bubble foam layer;

FIG. 12 a is a plan view of a possible embodiment of a nozzle; and

FIG. 12 b is a cross-sectional view of the nozzle of FIG. 12 a.

Reference numeral 1 in FIG. 1 denotes a device for preparing a beveragesuitable for human consumption and having a fine-bubble foam layer, suchas coffee or milk with a fine-bubble foam layer. The device 1 isprovided with a beverage unit 2 for delivering a beverage suitable forhuman consumption, coffee in this example, under pressure. The device 1is further provided with a nozzle 4. An outlet 6 of the beverage unit 2is connected to an inlet 10 of the nozzle 4 by means of a tube 8. Thenozzle 4 is thus in fluid communication with the beverage unit 2 for thedelivery of the beverage to the nozzle 4. The nozzle 4 thus generates ajet 12 of beverage. The device 1 is further provided with a receivingunit 14 into which the jet 12 is directed so as to obtain the beveragewith a fine-bubble foam layer. The receiving unit 14 is provided with achamber 16 which comprises at least one drain opening 18 for deliveringthe beverage with the fine-bubble foam layer. The receiving unit 14 isfurther provided with a jet impact member 20 that is at least partlyaccommodated in the chamber 16. The jet impact member 20 has a top 22which lies free from an inner wall 24 of the chamber and which isaccommodated inside the chamber. The nozzle 4 and the jet impact member20 are mutually oriented such that the jet 12 hits against at least aportion of the top 22 of the jet impact member 20, such that thebeverage 26 after hitting the jet impact member leaves the chamberthrough the at least one drain opening in the form of the beverage withthe fine-bubble foam layer. Surprisingly, air has been beaten into thebeverage in the chamber 16 in such a manner that a beverage with afine-bubble foam layer is obtained.

When hitting against the top 22 of the jet impact member 20, the jet 12in this example will form a mist and/or turbulence of the beverage whichflows against and/or along the inner wall 24 of the chamber 16 andsubsequently leaves the chamber through the drain opening 18 as thebeverage with the fine-bubble foam layer. It is achieved that the jet,when hitting against the top 22, forms a mist and/or turbulence ofbeverage which flows against and/or along the inner wall 24 of thechamber 16 in that the strength of the jet and the size of the chamberare mutually attuned. The jet must be sufficiently forceful and/or thechamber must be sufficiently small.

The moment the beverage unit 2 stops delivering the beverage underpressure to the nozzle 4, the formation of a mist of beverage in thechamber 16 will also stop. The chamber 16 will then be able to emptyitself quickly through the drain opening 18. The drain opening 18 inthis example has a diameter of 5 mm, with the result that the chamber 16is empty within a few seconds. A long period (tens of seconds) duringwhich the chamber 16 empties itself, including final dripping, does notoccur here.

The receiving unit 14 in this example is provided with a channel 28 withan inlet opening 30 and an outlet opening 32. The outlet opening 32 inthis example forms a product feed opening of the chamber 16 for thesupply of the jet 12 to the chamber 16. The nozzle 4 in this example isat some distance from the inlet opening 30 of the channel 28. As aresult, the jet 12 also sucks air 34 through the inlet opening 30 of thechannel 28 into the chamber 16 during operation. The product feedopening 32 of the chamber 16 here at the same time acts as an air supplyopening 32′.

Since a combination of the beverage jet and air is supplied to thechamber 16, air can be beaten into the beverage in cooperation with thegenerated stream of mist particles, whereby surprisingly a beverage witha fine-bubble foam layer is obtained. The air flow from the inletopening 30 into the chamber 16 achieves that the mist particles cannotleave the chamber 16 through the inlet opening 30. The air flow as itwere provides a sealing of the inlet opening 30 against mist particlesin the chamber 16. It is thus prevented that the mist particles can movetowards the nozzle 4 and interfere with the jet. The impact of the jet12 against a portion of the top 22 creates said mist particles duringoperation. These mist particles will first move upward and sidewaysimmediately after hitting against the top 22. A laminar and/or turbulentflow of mist particles thus arises in the chamber, which mist particleswill still be able to flow against and/or along the inner wall 24. Theforce of gravity will then cause the mist particles to move downward.The mist particles subsequently form a liquid beverage again, into whichair has been introduced such that a fine-bubble foam layer is formed,which beverage can subsequently leave the chamber 16 through the drainopening 18. The beverage is now ready for consumption.

It is true in this example that the top 22 of the jet impact member 20is present between the air supply opening 32′ and the drain opening 18.Furthermore, the top 22 is directed towards the nozzle 4. In thisexample, the top 22 is also located between the product feed opening 32and the drain opening 18. It holds in particular that the top 22 isdirected towards the product feed opening 32. A surface of the top 22 isconvex in shape. It is found in this case that the mist particles formedafter the impact initially move upwards distributed over a solid angleΩ.

In this example, a line 38 perpendicular to the surface 36 of the top 22in a position where the jet 12 hits the top 22 is at least substantiallyparallel to the jet 12. Furthermore, a perpendicular line 38 in thecenter of the surface 36 of the top 22 is at least substantiallydirected towards the nozzle 4 and towards the product feed opening 32.This perpendicular line, too, is at least substantially parallel to thejet. Moreover, a line 38 perpendicular to the surface 36 of the top 22in the position where the jet 12 is incident is directed towards theproduct feed opening 32, and also towards the nozzle in this example. Itis also true that the top 22 is in the center of the chamber 16, viewedin a plane 37 perpendicular to the jet. The inner wall 24 of the chamber16 in this example is at least substantially rotationally symmetricalwith respect to an axis of rotation 40. This axis in addition extends ina longitudinal direction of the chamber. Said center is a point of thisaxis of rotation 40 in this example. The jet impact member 20 in thisexample is in a lower portion of the chamber 16. The top is also presenton the axis 40 of the chamber. The jet impact member 20 has a poleconstruction in this example. An axial direction of the pole-shapedmember extends in a longitudinal direction of the chamber 16. The axisof rotation 40 mentioned above extends through the top 22. Arotationally symmetrical receiving unit 14 is thus obtained around thesymmetrical axis of rotation 40 in this example.

In this example, the distance H1 from the product feed opening 32 to thetop 22 is greater than the distance H2 from the top 22 to the drainopening 18 of the chamber 16. Also, in this example, H2 is greater thanzero. Since the mist flow is especially formed in the chamber 16 betweenthe top 22 and the product feed opening 32, a major portion of thechamber 16 can now be utilized for said laminar and/or turbulent flowsof the mist.

In FIG. 2, reference numeral 1 denotes a first embodiment of a deviceaccording to the invention. Components corresponding to those of FIG. 1have been given the same reference numerals. Since the device of FIG. 2largely corresponds to the device of FIG. 1, it is especially thedifferences between the devices of FIGS. 1 and 2 that will be discussedbelow.

The product feed opening 32 of the chamber in the device of FIG. 2 doesnot act as an air supply opening. The channel 28 here extends up to thenozzle 4. The air supply opening 32′ is omitted.

This implies that the device is constructed such that air 34 can besupplied to the chamber 16 exclusively through the at least one drainopening 18. It is found that a beverage with a fine-bubble foam layer isobtained by means of the device of FIG. 2 with properties comparable tothose of the beverage with the fine-bubble foam layer obtained with thedevice of FIG. 1. Since the air supply opening 32′ can now be dispensedwith, the device of FIG. 2 can be economically manufactured, if sodesired. The nozzle 4 in this example is connected to the chamber via afluid path extending from the nozzle to the product feed opening 32,which fluid path, formed by the channel 28 in this example, forms aclosure for the outside air, with the result that in this example theair 34 can only be supplied to the chamber 16 through the at least onedrain opening 18. The air will be sucked on in this example in that thebeverage with the fine-bubble foam layer leaving the chamber 16 throughthe drain opening causes an air flow which leaves the chamber throughthe drain opening. This causes an underpressure in the chamber, with theresult that at the same time air 84 is sucked into the chamber throughthe drain opening 18. This air flow accordingly compensates for the lostair carried along by the beverage when the latter leaves the chamberthrough the drain opening.

In FIG. 2, a cross-section of the chamber 16 is substantiallyheart-shaped. This, however, is not essential. This may be illustrated,for example, with reference to FIG. 3.

Components in FIG. 3 corresponding to those in FIG. 2 have been giventhe same reference numerals. An inner wall 24 of the chamber 16 in FIG.3 is now substantially cylindrical in shape for the major part.Furthermore, the surface 36 of the top 22 is of planar construction inthis example.

FIGS. 4 a and 4 b show an alternative embodiment of a device accordingto the invention. The device is provided with a unit 42 which comprisesa receiving unit 14. Components of the receiving unit 14 correspondingto those of FIGS. 2 and 3 have been given the same reference numerals asin FIGS. 2 and 3. The unit 42 is furthermore provided with the nozzle 4.In addition, the unit 42 comprises a holder 44 for accommodating a pad46 filled with a product to be extracted and/or dissolved, such asground coffee and/or a dairy creamer. The holder 44 and the pad 46 maybe of a type as described in European patent 904.717. The holder 44 isprovided with a bowl-shaped inner space 47 which is bounded by a bottom48 and an upright side wall 50. The upright side wall 50 extends aroundthe bottom. The bottom and the upright side wall thus define abowl-shaped inner space of the holder in which the pad is accommodatedduring use. The pad 46 extends over the bottom 48 up to the upright sidewall 50. At least one drain opening, formed by the nozzle 4 in thisexample, is provided in the bottom 48. This drain opening forms anoutlet of the holder. The inlet 10 of the nozzle in this example isaccordingly in fluid communication with the outlet of the holder,because the inlet 10 and an outlet 11 of the nozzle constitute theoutlet of the holder. In this example, moreover, grooves are provided inthe bottom of the holder. The device 1 is further provided with a lid 52with which the holder can be closed off. The device 1 also comprises ahot-water unit 54 for supplying hot water under pressure to an innerspace of the lid 52. The lid 52 is provided with a number of outletopenings 56 at its lower side. Hot water is thus supplied through theoutlet openings 56 at an upper side of the holder 44 during operation.The holder 44 and the hot-water unit 54 together form the beverage unit2 of FIGS. 2 and 3. It further holds in this example that the receivingunit 14 and the holder 44 are mechanically interconnected. The nozzle 4is mechanically connected to the holder 44. The nozzle 4, holder 44, andreceiving unit 14 thus form a mechanical unit. The air 32 again flowsthrough the drain opening 18 into the chamber 16. The jet impact member20 in this example is connected to the chamber 16 by means of threelateral arms 60.

The pad 46 extends over the bottom 48 of the holder 44 up to the uprightside walls 50 of the holder. The assembly of the pad 46 and the unit 42also forms part of the invention.

The device of FIGS. 4 a and 4 b operates as follows. The hot-water unit54 supplies hot water under pressure to the inner space of the lid 52.This hot water leaves the lid 52 under pressure through the outletopenings 56 of the lid 52. Hot water is thus supplied to the upper sideof the holder 44. This water is pressed through the pad 46, which isfilled with ground coffee in this example. A coffee extract is formedthereby which leaves the holder 44 through the nozzle 4. Since thecoffee extract is supplied to the nozzle 4 under pressure, a jet ofbeverage is now formed. This jet 12 hits against the top 22 of the jetimpact member 20 as discussed with reference to FIGS. 2 and 3. Air issupplied to the chamber 16 exclusively through suction of air via thedrain opening 18. The beverage with the fine-bubble foam layer, in thisexample the coffee extract with the fine-bubble foam layer, leaves thechamber 16 through the drain opening 18. The drain opening 18 in thisexample is formed by the openings formed between the lateral arms 60.

FIGS. 5 a and 5 b show a fourth embodiment of a device according to theinvention. Components corresponding to those of FIG. 4 have been giventhe same reference numerals. As in FIG. 4, the holder, the receivingunit comprising the chamber 16 and the jet impact member 20, and thenozzle 4 are mechanically interconnected into one unit 42. A first pad46.1 is accommodated in the holder 44 in this example, resting on thebottom 48. A second pad 46.2 is present above the first pad 46.1,resting substantially on the first pad 46.1. The first pad 46.1 againcomprises an envelope made of filter paper which in this example isfilled with a soluble substance. The soluble substance in this exampleis a dairy creamer. The second pad 46.2 is also provided with anenvelope of filter paper which in this example is filled with a productto be extracted. The product in this case is ground coffee. This ismerely an example, however, thus it is alternatively possible for thefirst pad 46.1 to be filled with a soluble product and for the secondpad 46.2 to be filled with a product to be extracted. Also, both thefirst and/or the second pad may be filled with a product to be extractedas well as a product to be dissolved.

Furthermore, the chamber 16 is provided with a product feed opening 32through which the jet generated by a nozzle 4 is supplied to the chamberduring operation. More in particular, the product feed opening 32 isformed by the nozzle 4 in this example.

It further holds that a space 60 within the chamber between the nozzle 4and the jet impact member 20 is free from restrictions for a flow of thebeverage between the nozzle and the jet impact member. This is incontrast to the device of FIGS. 2, 3, and 4, in which the channel 26 maybe denoted a restriction.

Hot water is supplied to the lid 52 by the hot-water unit 54 duringoperation. This hot water is supplied under pressure through theopenings 56 in the lid 52 to an upper side of the holder 44. This hotwater will thus be pressed through the coffee pad 46.2. The coffeeextract subsequently leaves the coffee pad at the lower side thereof andenters the milk pad 46.1. The dairy creamer present in the milk pad 46.1will subsequently dissolve in the coffee extract. The coffee extractwith the dairy creamer dissolved therein is subsequently supplied underpressure to the nozzle 4. A jet 12 of the beverage is created therebywhich hits against the top of the jet impact member 20. The beveragewith the fine-bubble foam layer, cappuccino in this example, willsubsequently flow from the drain opening 18, exactly as in the examplesdescribed above. Air 34 will be supplied through this drain opening tothe chamber, as discussed above.

FIGS. 6 a and 6 b relate to a fifth embodiment of a device according tothe invention. This device largely corresponds to the device of FIGS. 5a and 5 b. The holder 44, however, now accommodates a pad 46 filled withground coffee. Another difference with the device of FIGS. 5 a and 5 bis that here the jet impact member is provided with an air supplychannel 62 which extends from the exterior through the jet impact memberinto the chamber 16. The air supply channel comprises an inlet 63situated outside the chamber. More in particular, two air supplyopenings 64.1 and 64.2 are provided in a side wall of the jet impactmember, which openings are in fluid communication with the air supplychannel 62. During operation, air (from outside the chamber), will onlybe supplied to the chamber 16 through the air supply channel 62 and (inthis example also) via the drain opening 18. Air thus flows through theinlet 63 into the air supply channel and then enters the chamber throughthe air supply opening 64. Obviously, the side wall of the jet impactmember may be provided with different numbers of air supply openings 64.What is relevant in this example is that it is provided with at leastone air supply opening. The supply of air through the air supply channel62 takes place exactly as discussed above. Since the beverage 26 withthe fine-bubble foam layer flows from the chamber through the drainopening, an underpressure is created in the chamber 16 whereby air 34 issucked on through the air supply channel 62 and through the drainopening 18.

FIGS. 7 a and 7 b show a sixth embodiment of a device according to theinvention. This corresponds at least substantially to the embodiment ofFIGS. 5 a and 5 b. A difference is again that only one pad isaccommodated in the holder 44 in the form of a coffee pad as discussedwith reference to FIGS. 6 a and 6 b. Another difference with the deviceof FIGS. 5 a and 5 b is that the jet impact member 20 is not connectedto the chamber 16. The holder 44, the nozzle 4, and the chamber 16 aremechanically interconnected in this example so as to form a unit 42′.This unit 42′ rests, for example, on support means 65 of the device.When the lid 52 is removed, the unit 42′ can be lifted from a portion 66of the device to which the jet impact member 20 is fixedly connected.The portion 66 of the device may additionally be provided with an inletopening 68, while the jet impact member 20 is connected to said portion66 of the device by means of lateral arms as discussed with reference toFIGS. 4 a and 4 b. It is furthermore apparent from FIG. 7 a that a lowerside 69 of the chamber 16 also lies free from the portion 66 of thedevice. The operation of the device of FIGS. 7 a and 7 b is fullysimilar to what was discussed with reference to FIGS. 5 and 6. Thebeverage leaving the drain opening 18 can flow away through the opening68 in the device and/or through an intermediate space 70 between a lowerside 69 of the chamber 16 and the portion 66 of the device. Air can besupplied to the chamber 16 exclusively through the drain opening 18 ofthe chamber. This air is then supplied to the drain opening 18 of thechamber via the opening 68 and/or via the intermediate space 70 betweenthe chamber and the portion 66 of the device. It is also possible thatthe lower side 69 of the chamber will bear on the portion 66 of thedevice during operation, in which case the space 70 between the lowerside 69 of the chamber and the portion 66 of the device is absent. Inthat case the beverage 26 flowing through the drain opening can flowaway through the opening 68 in the portion 66 of the device. In thatcase air can only be supplied through the opening 68 and subsequentlythrough the drain opening 18 to the chamber 16.

FIGS. 8 a and 8 b show a seventh embodiment of a device according to theinvention. Again, components corresponding to those of FIGS. 2 to 6 havebeen given the same reference numerals. It is again true in the deviceof FIGS. 8 a and 8 b that the device is provided with a mechanical unit42′ composed of the holder 44, the nozzle 4, and the chamber 16. The jetimpact member 20 again does not form part of this mechanical unit 42′and is fixedly connected to another portion 66 of the device. The jetimpact member 20 in this example is again provided with an air supplychannel extending through the jet impact member into the chamber 16. Thepreparation of the beverage takes place entirely as discussed above. Thefinished beverage 26 will again leave the chamber through the drainopening 18. In this example, the beverage now flows away through theintervening space 70 between the lower side 69 of the chamber 16 and theportion 66 of the device. Air is supplied to the chamber only throughthe air supply channel 62 and possibly in this example also, though to alesser extent, through the at least one drain opening 18.

The invention is not limited to the embodiments discussed above. Thus aplurality of jets may impact on the jet impact member 20 instead of onejet. A plurality of nozzles 4, each directing a jet towards the jetimpact member 20, may then be used. It is also possible for the nozzle 4to be provided with a plurality of outlets for generating a plurality ofjets. The plurality of jets may also be incident on a plurality of jetimpact members accommodated in the chamber 16. The plurality of jets mayalternatively be incident on one jet impact member. It is furthermoreconceivable that the chamber is provided with a plurality of jet impactmembers 20 which are each hit by at least one jet originating from, forexample, a plurality of nozzles or a single nozzle. It is also possiblein the device of FIG. 4 that a fluid communication, for example in theform of a tube, is present between the outlet of the holder and theinlet of the nozzle. The jet impact member may have the shape of aplanar plate, as was stated above. The top 22 may alternatively beconvex as shown in FIG. 2, while holes running from top to bottom areprovided in the top 22 adjacent an edge 23. The top 22 may also beconcave, see FIG. 9. Furthermore, the top 22 may be concave along itsouter circumference with a tip in the center, see FIG. 10. The receivingunit 14 may also be constructed as shown in FIG. 11. Furthermore, thejet impact member may be replaced by a cylinder or tube in the device ofFIGS. 2 to 8 and 11, extending in horizontal direction in the drawingbetween the walls 24 of the chamber. The portion of an outer side of thecylinder or tube against which the jet can hit will then form the top ofthe jet impact member which lies free from the walls 24. The diameter ofthe cylinder or tube may be, for example, equal to the diameter of thetop in FIGS. 2 to 8 and 11.

The nozzle may alternatively be formed, for example, by a nozzle asdescribed in EP 1 092 377. The nozzle may also be formed by a plate 100with an opening 102 as shown in FIGS. 12 a and 12 b. The thickness b ofthe plate is, for example, 0.1 to 0.5 mm, preferably 0.2 to 0.4 mm.

It is true then in FIG. 11, for example, that d1<d3.

It is also true, for example, that d3<d2 for each embodiment (cf., forexample, FIGS. 3 and 11). It is also possible to opt for d1=d2, so thata space within the chamber between the nozzle and the jet impact memberis free from restrictions for a flow of the beverage between the nozzleand the jet impact member. The channel 28 then in fact forms part of thechamber 14. The nozzle 4 now is the product feed opening of the chamber14.

The following further remarks are particularly relevant.

The diameter of the jet when issuing from the nozzle may vary, forexample, from 0.2 to 1.6 mm, more in particular from 0.4 to 1.4 mm,preferably from 0.6 to 1 mm, and more preferably from 0.7 to 0.9 mm.This diameter is approximately 0.8 mm in the present example.

The diameter of the top (for example d3 in FIG. 11) may vary, forexample, from 1.4 mm to 10 mm, more in particular from 1.5 mm to 8 mm,preferably from 1.75 mm to 5 mm, and more preferably from 1.75 to 3.0mm. This diameter is 2 mm in the example.

The diameter of the chamber at the area of the top (for example d2 inFIGS. 3 and 4) divided by the diameter of the top (for example d3 inFIGS. 3 and 11) is, for example, greater than 1.1, preferably greaterthan 1.2, and more preferably greater than 2.0. Said ratio is preferablyapproximately equal to 2.5. The ratio d2/d3 determines the extent of theoutflow of the beverage. When this ratio is increased, more space iscreated for the supply of air, which leads to a coarser foam. When thediameter d2 remains the same and d3 is made greater, for example, thefoam becomes finer. The ratio d2/d3 could be made variable in that thediameter d2 and/or the diameter d3 is made adjustable in a known manner.This adjusting possibility may also be achieved by means of a ringclosed around the jet impact member, so that the diameter d3 isincreased, or a ring fastened against the inner wall of the chamber, sothat the diameter d2 is decreased. Various rings may thus lead tovarious diameters d2 and/or d3. It is also possible to change the sizeof the flow surface area between the inner wall and the jet impactmember in other manners, for example a ring arranged between the jetimpact member and the inner wall of the chamber, which ring lies freefrom the jet impact member and from the inner wall. The surface areathrough which the beverage can flow out will also be reduced if the jetimpact member increases in diameter from the top in a direction towardsthe drain opening inside the chamber. The supply of air need not beaffected thereby if the jet impact member is provided with said airsupply channel.

Furthermore, the surface roughness of the jet impact member and/or theinner wall may be varied. A comparatively smooth surface, for example,could yield a finer foam than a surface that is comparatively rough. Thechamber 16 need not be cylindrical or rotationally symmetrical, it mayhave alternative shapes. Thus a cross-section of the chamberperpendicular to the axis 40 may have, besides a circular shape, atriangular, rectangular, square, or any other, non-symmetrical shape.

The jet impact member 20 is in the center of the chamber 16 in theexamples given. It is also conceivable, however, that the axis 48 of thechamber does not coincide with a center of the top of the jet impactmember. It is accordingly also possible that the jet impact member,viewed in a plane perpendicular to the axis 40 of the chamber, ispositioned out of center in the chamber, as long as the jet hits the jetimpact member. In other words, the distance between the jet impactmember and the chamber wall may vary. The chamber may also have anon-rotationally-symmetrical shape in this case, as discussed above.

Furthermore, it is true that said ratio may be, for example, smallerthan 5. Said ratio may vary from 1.1 to 5, preferably from 1.5 to 4, andmore preferably from 1.75 to 3. The top of the jet impact member may bemade, for example, from POM, PP, ABS, or metal.

The diameter d4 of the opening (inlet) 10 of the nozzle may vary, forexample, from 0.3 to 1.5 mm, preferably from 0.6 to 1.0 mm, and morepreferably from 0.7 to 0.9 mm. The term “nozzle” is understood to denoteany means for generating a jet.

A greatest diameter d5 of the chamber may be, for example, 1 to 4 timesgreater, preferably 1 to 3 times greater than the diameter d2 of thechamber at the area of the top (cf., for example, FIG. 2). A diameter ofthe drain opening 18 of the chamber may vary, for example, from 3 mm to15 mm, preferably from 2.5 mm to 8 mm, and more preferably from 4 mm to6 mm.

The orientation of the devices of FIGS. 2 to 12 is not relevant. Thusthe device of FIG. 4 may be tilted or even placed upside-down. Theconstruction of the system will obviously have to be adapted in thatcase, as will be evident to those skilled in the art. The beveragesupplied to the nozzle may also comprise a concentrate that is yet to bediluted with water after delivery by the device. The beverage suitablefor consumption in that case is a concentrate yet to be diluted. Theholders 44 discussed above may alternatively be provided with a filterbottom which is known per se, so that the holders 44 may be filled withloose products to be extracted, such as coffee and/or tea and/or otherloose products to be dissolved such as a dairy creamer. A product to bedissolved in the present application is also deemed to denote otherproducts such as a product for the preparation of cocoa and flavoringagents. A product to be extracted may also be a product other thancoffee or tea.

Such modifications are all deemed to fall within the scope of theinvention.

The invention claimed is:
 1. A unit for preparing a beverage with a foamlayer, the unit comprising: a beverage unit configured to supply thebeverage under pressure; at least one nozzle which is in fluidcommunication with the beverage unit and configured to supply thebeverage to the nozzle such that the nozzle generates a jet of thebeverage; and a receiving unit into which the jet is directed includinga chamber having at least one drain opening configured to deliver thebeverage with the foam layer, and a jet impact member located at abottom of the chamber and having a top separated from an inner wall ofthe chamber, the nozzle and the jet impact member being oriented suchthat during operation the jet hits against at least a portion of the topof the jet impact member so that the beverage, after hitting against thejet impact member, leaves the chamber through the at least one drainopening in the form of the beverage with the foam layer, wherein theunit is constructed such that air is supplied to the chamber through atleast one of said at least one drain opening and through an air inletchannel which extends through an inner channel within the jet impactmember into the chamber.
 2. The unit claimed in claim 1, furthercomprising a holder for accommodating a product to be at least one ofextracted and to be dissolved, wherein the holder, the chamber the jetimpact member, and the nozzle are mechanically connected to one another,and wherein the holder comprises at least one outlet which is in fluidcommunication with an inlet of the nozzle.
 3. The unit as claimed inclaim 2, wherein the holder is provided with a bottom and an uprightside wall which extends around the bottom, wherein said bottom comprisesthe at least one outlet.
 4. The unit as claimed in claim 2, wherein theholder is designed to be filled with at least one pad which comprises anenvelope of filter paper and which is filled with the product to be atleast one of extracted and to be dissolved.
 5. The unit as claimed inclaim 1, wherein the unit is constructed such that air is supplied tothe chamber exclusively through said at least one drain opening andthrough said air inlet channel, the unit further comprising a holder foraccommodating a product to be at least one of extracted and to bedissolved, wherein the holder, the chamber, and the nozzle aremechanically connected to one another, and wherein the holder comprisesat least one outlet which is in fluid communication with an inlet of thenozzle.
 6. The unit as claimed in claim 5, wherein the holder isprovided with a bottom and an upright side wall which extends around thebottom, wherein the bottom comprises the at least one outlet.
 7. Theunit as claimed in claim 5, wherein the holder is configured to hold atleast one pad comprising an envelope of filter paper and filled with theproduct to be at least one of extracted and to be dissolved.
 8. The unitas claimed in claim 2, further comprising at least one pad comprising anenvelope of filter paper filled with the product to be at least one ofextracted and to be dissolved, wherein the pad is accommodated in theholder and extends therein over a bottom of the holder up to an uprightside wall of the holder.
 9. The unit as claimed in claim 8, wherein theat least one pad comprises one of coffee, tea, and a dairy creamer. 10.The unit claimed in claim 3, wherein the holder is designed to be filledwith at least one pad which comprises an envelope of filter paper andwhich is filled with the product be at least one of extracted and to bedissolved.
 11. A unit for preparing a beverage with a foam layercomprising: a beverage unit to supply the beverage under pressure andleast one nozzle in fluid communication with the beverage unit to supplythe beverage to the nozzle so the nozzle generates a jet of thebeverage; and: a receiving unit into which the jet is directed includinga chamber having a drain opening to deliver the beverage with the foamlayer, and a jet impact member located at a bottom of the chamber havinga top separated from an inner wall of the chamber, the nozzle and thejet impact member being oriented such that during operations the jethits against at least a portion of the top of the jet impact member sothat the beverage, after hitting against the jet impact member, leavesthe chamber through the drain opening in the form of the beverage withthe foam layer, wherein the unit is constructed such that air issupplied to the chamber exclusively through the drain opening.
 12. Theunit as claimed in claim 11, further comprising a holder foraccommodating a product to be at least one of extracted and to bedissolved, wherein the holder, the chamber, the jet impact member, andthe nozzle are mechanically connected to one another, and wherein theholder comprises at one outlet which is in fluid communication with aninlet of the nozzle.
 13. The unit as claimed in claim 12, wherein theholder is provided with a bottom and an upright side wall which extendsaround the bottom, wherein said bottom comprises the at least oneoutlet.
 14. The unit as claimed in claim 12, wherein the holder isdesigned to be filled with at least one pad which comprises an envelopeof filter paper and which is filled with the product to be at least oneof extracted and to be dissolved.
 15. The unit as claimed in claim 11,the unit further comprising a holder for accommodating a product to beat least one of extracted and to be dissolved, wherein the holder, thechamber, and the nozzle are mechanically connected to one another, andwherein the holder comprises at least one outlet which is in fluidcommunication with an inlet of the nozzle.
 16. The unit as claimed inclaim 15, wherein the holder is provided with a bottom and an uprightside wall which extends around the bottom, wherein the bottom comprisesthe at least one outlet.
 17. The unit as claimed in claim 15, whereinthe holder is configured to hold at least one pad comprising an envelopeof filter paper and filled with the product to be at least one ofextracted and to be dissolved.
 18. The unit as claimed in claim 12,further comprising at least one pad comprising an envelope of filterpaper filled with the product to be at least one of extracted and to bedissolved, wherein the pad is accommodated in the holder and extendstherein over a bottom of the holder up to an upright side wall of theholder.
 19. The unit as claimed in claim 18, wherein the at least onepad comprises one of coffee, tea, and a dairy creamer.
 20. The unit asclaimed in claim 13, wherein the holder is designed to be filled with atleast one pad with comprises an envelope of filter paper and which isfilled with the product to be at least one of extracted and to bedissolved.